1997 1900 DC issues

I run a 1900dc when autos are on the left side jumps up and down erratically. Moba controllers and it seems it is always searching. We switched the solenoids and the right side started to jump. We got 2 new solenoids and it didn't fix the problem? Anyone ever encounter this problem? Yes we switched the boxes and bought new sonic sensors checked the cables. Any input or recommendations are appreciated.

press the s until it says sen. then use the calibrate buttons to lower the sensitivity by going up in number. 5 is stock going toward 10 should make it less jumpy if I remember right. DC's weren't proportional they just bump up and down to make grade. they all jump a little when your sitting still. we used to just shut off the autos when we weren't moving. hope this helps

Thnx for the reply Jeff and yes I have adjusted the Sensitivity on the box and set it to the lowest. I don't think it is proportional because there are only 2 settings for the Sen Stan. & Low but if that's the nature of the beast with these old machines then so be it. Just odd it only does it on the left side the right side is fairly smooth.

1900DC's had non-proportional (on-off) grade control valves, there is also a throttle valve that is adjustable as well as orifices at the valves and at the hydraulic fittings going into the top of the cylinders. These components are all there to slow down the hydraulic reaction time of the grade system and make it smoother operating and if the orifices are removed it will become very bumpy in operation. The orifice size is 1.0 or 1.5mm, the throttle valve makes only a small difference in cylinder speed when adjusted. The most likely thing is that the orifices were lost when a grade control valve was changed, its easy to do. You have to dismantle the valve stack for the leg involved, located under the operators floor, to see if the orifice is still there. Its a little steel plate about the size of a dime sandwiched between the valves.

Ty Huskyrider your a good man